A camera module generally comprises a substrate, an image sensor, a lens holder, and a lens barrel. The image sensor and the lens holder are fixed on the substrate. The lens barrel is received in the lens holder. The lens barrel and the lens holder are usually fixed by glue. However, the adhesion force between the lens barrel and the lens holder is not strong enough, which may cause the lens barrel to be separated from the lens holder during transport, assembling, or reliability testing, resulting in deterioration of the image quality of camera module. Improvements in the art are preferred.